Automatic carton sealing apparatus



May 2, 1961 D. B. HoPKlNsoN 2,982,054

AUTOMATIC CARTON SEALING APPARATUS Filed Oct. 14. 1959 2 Sheets-Sheet l 7 3 2 wf A 1 4 2 m7 2 .g 232| 1s 7722 7mm. E 48 1 3 y 5 w 2 d J5. 9 8 19 b o, 8M 6 \O w 9 j# 1E o a m2 w3 HH no@` 8 87 811H, 7 354. 6^ 6,- 3;T l

May 2, 1961 D. B. HoPKlNsoN 2,982,064

AUTOMATIC CARTON SEALING APPARATUS Filed Oct. 14. 1959 2 Sheets-Sheet 2 IIIIBO l 139 w 15?? [i] PHOTO CONTROL 132 141 102 @j 104 103 j i3 l 105 109 125 119 46 83 6s use 1/08 13s Fig. 4.

117 115x: I( l 130: l I l I INVENTOR.

mmm B. HopmzvsoN Fzg www v'- PM/:ALM p TTRNEYS United States Patent O AUTOMATIC CARTON SEALING APPARATUS David Hopkinson, Portland, Maine, assignor to Southworth Machine Company, Portland, Malne, a corporation of Maine Filed Oct. 14, 1959, Sel'. No. 846,378

9 Claims. (Cl. Sli-76) This invention relates to a machine for tightly sealing large cartons such as are used to package rearns of .lat paper sheets or the like.

In the pape'r manufacturing art, the sheets of paper are usually stacked on pallets in untrimmed condition. Approximately a ream at a time is removed from the stack and passed through a trimming machine, of the guillotine knife type, wherein the four edges of the ream are accurately trimmed. The trimmed ream is then placed in the bottom portion of a paperboard carton, the upper portion of the carton placed over the lower portion and the two portions adhered to each other to tightly encase and seal the ream. It is essential that the ream of paper be so snugly fitted in the carton that there is no space for shifting of the sheets since the edges must be kept ush and the faces unwrinkled.

It has heretofore been proposed to accomplish the seal-` ing of such cartons by vacuum means, the cartons being manually advanced to a sealing station, a exible diaphragm lowered over the carton and air exhausted from under the diaphragm. By this means the side walls of the cover are forced to fold accurately around the top of the ream, no air space remains within the carton and the ream is hermetically enclosed in what amounts to a skin tight paperboard package. l am aware of a prior patent application, Serial No. 749,531, filed July 18, 1958, now U.S. Patent 2.932.927 to Segerstrom et al. of April i9, 1960, entitled Carton Sealing Machine," and this application is intended to cover improvements made by me in Asuch apparatus.

It is the obict of this invention to provide vacuum carton sealing apparatus whichv is fully automatic in that the cartons are advanced on a power conveyor, automatically halted, automatically sealed and then automatically discharged from the apparatus.

Another object of the invention is to provide carton sealing apparatus of the vacuum diaphragm ytype wherein the diaphragm frame is lowered by its own weight only rather than under power. Thusthere is no danger to the operator of having yhis hands or arms crushed by the frame.

A further object of the invention is to provide vacuum sealing apparatus which is fully automatic and which can automatically adapt itself to` cartons of various sizes without .requiring adjustments t `Still another object of the invention is to provide a vacuum sealing table having `a novel pattern of air exhaust portSoOperableiWith-anrimpervious, endless belt conveyor 'whereby the beltcarries a cartn between the ports 'without adversely' 'lask'iiigv the same or preventing air exhaustion. f 'l A stillfflt'rther object ol` the invention is to provide carton sensingy means,l conplected in s'e'riesjeacllA means birigjcapble 'ot' `se'nsir'i'gizft vcartorl yof different dimensions andsef'h mng the erroniprecisely ,inthe `entre of a vacuumsga'itlstatignottone.v l

.and aimera Qfhe sismica will. be

apparent from the claims, the description of the drawings and from the drawings in which Fig. l is a side elevational view of a machine constructed in accordance with the invention.

Fig. 2 is a plan view of the machine illustrated "n Fig. l.

Fig. 3 is an end view of the machine illustrated in Fig. l from the carton discharge end.

Fig. 4 is an electrical diagram of the apparatus of the invention.

Fig. 5 is a fragmentary, enlarged detail plan view of the limit switch mechanism, and

Fig. 6 is a side view of the device shown in Fig. 5.

As shown in the drawings, the improved vacuum carton sealer 20 of this invention includes the table 21, having a base, or frame 22 and a horizontalupper face, or table top 23. A carton conveyor 24 of a conventional type, is provided to feed unsealed cartons individually and successively onto the upper face 23 and a similar conveyor 25 is provided at the opposite end of the table to carry the sealed cartons to any desired destination. Each carton 26 includes a lower tray-like portion 27 and an upper portion 28 which may have downwardly prefolded but unsealed wall flaps or which may be a at blank with precreased wall aps 29, the wall flaps having adhesive thereon ready for sealing to the lower portion.

The ream, or pile, 3l of paper sheets is preferably of greater height than the side walls of the lower portion 27 so that the upper portion or cover can be drawn down tightly therearound, al1 air expelled and the wall llaps of the upper and lower portions lrmly adhered to cach other. It will be understood that accuracy and perfect packaging are more desirable than high speed of operation for the reason that a paper trimmer must trim all four edges of a ream in successive steps whereby its production is relatively slow. Thus the sealer 2t) can operate intermittently to advance an unsealed, tilled carton across the upper face 23, from the conveyor 24 to the sealing station, or zone, 32. to then halt at station 32 for a period such as ten seconds while the carton is sealed and the adhesive dried, and to then advance the sealed carton out of station 32 across the upper face 23 to the conveyor 25.

The cartons are advanced across the upper face 23 by a power operated conveyor 33 formed by an impervious flexible endless belt 34 trained around the end drums 35 and 36. Drums 35 and 36 are journalled in frame pieces such as 37 of table 21, the upper stretch 38 extending from end to end of the table and overlying a central, longitudinal strip of the upper face 23. The lower stretch 39, of belt 34, is trained around an idler drum 4l, a drive drum 42 and a tension drum 43, the drive drum 42 being connected by a suitable power train 44 to the reduction unit 45 and electric drive motor 46.

The carton sealing station 32, of table 21, includes an air exhaust port 50, in the centre of the table, four radially extending grooves 51, 52, 53 and 54 underlying the upper stretch 33 of belt 34 and four right angular grooves S5, 56. 57 and S8 each at the terminal end of one of the radial grooves. Each right angular groove such as 5S includes a leg 59 parallel to and alongside the be apparent that the exhaustion of air from the central port S0 will tend to create a vacuum under any object resting on the portion ot upper face 23 outlined by the grooves. Theport 50 is connected by4 an air conduit 62 to a vacuum receiver tank 63 and to a vacuum pump 64,

lthere beiuga so,lenoid air valve. 65 in conduit 62 forassaults` controlling the exhaustion of air from port $0. The vacuum pump 64 is power operated by an electric motor 66, in a well known manner, to maintain the vacuum in tank 63 at a predetermined amount such as five (5) p.s.i. absolute or 20 inches Hg vacuum and the vacuum is adjustable from live to twenty inches of mercury.

Flexible, impervious diaphragm means 68 is provided in the form of the horizontally disposed blanket, or diaphragm, 69 draped across and supported from the rectangular frame 70 of rigid material such as wood or light metal. Diaphragm 69 may be of rubber, plastic or the like and the frame 'I0 is substantially coextensive in area with the area of station 32 dened by the pattern of air exhaust ports, slots or grooves in the upper face 23. The frame 70 and diaphragm 69 are normally poised at a spaced distance above the upper face 23 by means of four guide rods 71, 72, 73 and 74 each at a corner of the frame and each slidable vertically in suitable holes, or sockets, such as at 75 in the table 21. The lower end of each of the guide rods is connected to a flexible strap such as 76, by a suitable bracket 77, each strap 76 passing over pulleys such as 78 and 79 and having its opposite end connected to the terminal end 80 of one of a pair of crank arms such as 81, each on an opposite side of the machine 20. The crank arms such as 81 are each mounted on a lateral shaft 82 which is rotatably driven by a suitable reduction unit and electric motor 83. For convenience I call the motor 83 the diaphragm motor and I call the motor 46 the conveyor motor. It should be noted that the frame 70 is raised by power but that it lowers by gravity only under the weight of the diaphragm, frame and rods, thereby avoiding any danger to the operator. When the arm 81 rotates clockwise from its uppermost position to its lowermost position it `pulls downwardly on the four straps such as 76, thereby lifting the frame to its normal position. When arm 81 rotates back to its'uppermost position, pull is released from the straps and the frame drops downwardly by gravity. Y'

Multiple, electric, carton-sensing means 85 is provided for the purpose of halting the conveyor 33, with the carton carried thereon precisely and accurately in the centre of the sealing station 32, regardless of variation in the dimensions of the carton. In the machine illustrated, there are three sizes of carton customarily used, as indicated in dotted lines in Fig. 1 at 86, 87 and 88, and therefore three sensing units 90, 91' and 92 are shown. Carton sensing means 85 is mounted on table 21 proximate the delivery encl of sealing station `32 and above the level of the upper face 23 of the table. A pair of upstanding framepieces 93 and 94 are fixed, each on an opposite side of table 2l and alongside the path of cartons advanced into station 32 by conveyor 33. Framopiece 93 carries three individual light sources 95, 96 and 9'7 while framepiece 94 carries three individual photo electric tubes, cells, transistors or other light sensitive devices 98, 99 and 100 opposite their respective light sources, whereby three separate light beams are simultaneously projected across the path of the leading'walls olthe cartons on conveyor 33. A

Each individual carton 4sensinglmeans.y su'chas 95 and 98,` 96 and 99 and 97 and 100 is staggered vertically and horizontally relative to the path lof-the cartons in spaced apart relation along aninclined' plane so that the light beam of'each means will `be interceptedand broken by thetleadingwall of a particularlyd'imensioned carton such as 86, 87 or 88. The individual sensing-means are connected to each other imseries whereby --intlividuall ad successive cartons, regardless of dimension will actuate the photo switch control means 102: y 1Means-i102 may huiof-i-tlre type designated photoufelectrio-icontroltype' 2913.11 manufacturedaby Photoswitoh ilncadf Qa'mbldg, Massachusetts, and =sliown cliriigrarnmatifettlly"4 in Fig;- 4.a The control means A:.102 automaticallyl moves thf a'rmaf 1 tum llfromutetrisninali 101|' tifftifnilitr'tl1055t`iflaen-i-th'i light beam of any one of the carton sensing means is intercepted. Normally the conveyor motor 46 is energized by a circuit including a source of electro motive force not shown, main conductor 106, photo control means 102, armature 103, terminal 104, conductor 107 and main conductor 108. This circuit is opened by the armature 103, in being moved to terminal 10S and a new circuit is closed including main conductor 106, photo control 102, armature 105, conductor 109, diaphragm frame motor 83, the armature 111 of switch 112, the armature 113 of switch 114 andmain conductor 108. Thus the conveyor halts and the diaphragm drops by gravity onto the upper face 23 at the sealing station 32.

Upon arrival of the frame 70, on the upper face 23 of table 21, first limit means 115 is actuated, the means 11S including the armature 116 of limit switch 117, thereby completing a circuit including main conductor 106, conductor 118, armature 116, timer 119, conductor 121 and main conductor 108. Timer 119-may be of a type commercially available from the Industrial Timer Corporation of Newark, New Jersey, and upon actuation of the timer, relay 122 isenergizedto open switch 112 and close a switch 123. The diaphragm motor is thus deenergized while a circuit is completed including main conductors 106 and 108, solenoid valve 65, switch 123 and conductors 124 and 125. Valve 65, thereupon exhausts air from under diaphragm 69, to downfold and vacuum seal the carton at station 32, for the period set by the timer such as ten seconds. When timer 119 times out, relay 122 is deenergiz'ed to open switch 123 to valve 65 and again close switch 112 to the diaphragm frame motor 83, thereby energizing the motor and causing the frame and diaphragm to rise to their normal position poised above the upper face 23.-

Second limit means 131) is providd including, the armature 131 of a switch 132which is normally open but closed by the arrival of the diaphragm frameY at its uppermost position. Switch 132 closes a circuit including main conductors 10'6 and 108, conductor 133, switch 132, a control relay 134, a switch 135 and conductor 136. The control relay 134 energizes a relay 138 which opens a switch 114 tothe diaphragm frame motor 83 thereby stopping the sarne and rnergizes a relay `139 which closes a switch 141 forholding in `relay 134 when the limit switch 132 opens and` which relay also Closes a switch 142 which energizcs conveyor motor 46 through conductor 143 while bypassing .photocontrol 102,. The conveyor then 1movesl the sealed .cartonto the delivery end of table21, beyond the lightqbcams of the photo switches. When all of'the light beams of the series connected photo switches are restored, the photo control 102 moves armature 103` over to terminal 104 thereby permitting the conveyor to continue runningrand also opens switch 135 to drop out relay 134V and res't the system.

Switch 135 is openedby means ofea relay 137,energized by photo control 102 when thearm l03-lips from terminal 105 back to terminal 104 thus indicatingthat the system is all clear and ready for` receiving the next succeeding carton.

As shown `in Figs. 5 and; I prefer to lmount limit switches 117 and 132 at the side of table 21;.proximate the -shaft 82, for timed actuation in accordance.` with the rotation of shaft 82 andjcrank am 81'.. ;A llong arm 144 is xed t,o.shaft.82to .rotatetherewith andlto, engage the switchA 117 4whentlre.shaft SLhasfpermitted theI frame to drop onto.the upper face 12,3. rit-,short arm 1451s also fixedy to shaft 82 to rotatetherewth F ateddonly by its respective fam.`

and to engage the switch 132 when .thew'sljiafttll` has lifted' thei'frane to iis" itill" raised position.; arms luana 145 rotate-m diffrent .ptanesand t switches are 'similarly psitit'lned so" tiifttvearsfifswittltV will; bev acuti.

while clearing the roller on limit switch 132. The arm 145 is shorter than arm 144 and strikes the roller on limit switch 132.

I claim:

1. In a carton sealer of the vacuum type, the cornbination of a table having a pattern of air exhaust ports in the upper face thereof outlining a carton sealing station; flexible, impervious diaphragm means, coextensive with the area of said station, vertically movable on said table and normally poised at a spaced distance above said upper face; a carton conveyor mounted on said table, said conveyor extending across said upper face from one end of said table to the other for advancing cartons up to, and away from, said sealing station; multiple, electric, carton-sensing means, mounted on said table alongside the path of a carton on said conveyor proximate one end of said sealing station, said sensing means being spaced apart and connected to each otherin series for actuation by cartons of different dimensions; power operated means for raising said conveyor; power operated means for raising said diaphragm means; power operated air exhaust means for exhausting air from said ports; electric control means, responsive to actuation by any one of said sensing means, to halt said conveyor and lower said diaphragm means by its own weight only; rst limit means, responsive to the arrival of said diaphragm means on the upper face of said table to actuate said air exhaust means for a predetermined period for vacuum sealing a carton at said sealing station and to then raise said diaphragm means and second limit means, responsive to the arrival of said diaphragm means at its raised position to restart said conveyor, to temporarily deactuate said sensing means and to then reactuate said sensing means.

2. A combination as specied in claim 1 wherein said carton conveyor is of less width than the width of the carton sealing station outlined by said exhaust ports and extends along a central strip thereof only.

3. A combination as specified in claim 1 wherein said diaphragm means includes a frame supported on rods slidably mounted in said table and llexible straps trained around pulleys connecting said rods to said power operated diaphragm raising means.

4. A combination as specified in claim 1 wherein said carton conveyor is an endless belt having an uppel stretch overlying a central strip of the upper face of said table intermediate of said pattern of exhaust ports.

5. A combination as specified in claim 1 wherein said multiple, carton sensing means comprises at least three photo switches, spaced vertically and horizontally from each other in an inclined plane to establish at least three light beams of different heights for interception by the leading walls of cartons advanced by said conveyor.

6. A diaphragm type carton sealer comprising a table having power operated air exhaust means in the upper face thereof; power operated, vertically movable diaphragm means normally poised above the upper face of said table; power operated conveyor means for advancing cartons of different dimensions individually and successively across the upper face of said table and under said diaphragm means; a plurality of spaced photo cell units mounted above the level of the upper face of said table alongside the path of cartons advanced thereacross by said conveyor, said units being connected to each other in series and producing multiple light beams across said path, each beam for interception by the leading walls of one of said cartons of a particular dimension; means responsive to the interception of any one of said light beams by a carton for halting said conveyor means and lowering said diaphragm means over said carton; means responsive to the lowering of said diaphragm means for actuating said air exhaust means for a predetermined period and then raising said diaphragm means to its normal position and means responsive to the raising of said diaphragm means for restarting said conveyor means, temporarily deactuating said photo cell units and then reactuating the same for sensing the arrival of the next carton on said conveyor means.

7. A combination as specified in claim 6 wherein said air exhaust means in the upper face of said table includes a central exhaust outlet port, four grooves extending substantially radially outwardly from said port toward the corners of said table and four right angular grooves, each proximate a corner of said table and connected to the outer end of one of said radial grooves.

8. A combination as specified in claim 6 wherein said vertically movable diaphragm means includes a flexible, impervious diaphragm, a rectangular frame of rigid material supporting said diaphragm and frame guide rods slidably mounted in said table for retraction by the weight of said frame only.

9. Apparatus for sealing cartons of different dimensions, sad apparatus comprising endless belt conveyor means for advancing cartons of predetermined different dimensions individually and successively along a straight, horizontal path through a carton sealing zone; at least three photo switches each mounted at a predetermined different horizontal and vertical position on said apparatus proximate the end of said carton sealing zone and above the level of said conveyor means, said units being connected to each other in series and producing at least three horizontally and vertically spaced light beams extending across the path of cartons carried by said conveyor means; electric control means responsive to the interception of any one of said light beams, by any carton of one of said predetermined different dimensions for deactuating said conveyor means with a carton precisely centered in said zone according to its dimensions and vacuum sealing means, in said zone, for sealing each said carton halted therein and then actuating said conveyor means to carry the sealed carton out of said zone.

References Cited in the fle of this patent UNITED STATES PATENTS 711,211 Honiss Oct, 14, 1902 2,639,567 Murdoch et al May 26, 1953 2,676,440 Campbell Apr. 27, 1954 2,909,875 Imbs Oct. 27, 1959 2,919,527 Smith Jan. 5, 1960 2,932,927 Segerstrom et al. Apr. 19, 1960 

